A Promise
by broadwaybound9
Summary: Lily makes one grave mistake that ends up affecting her life, Harry's, and Snape's forever. Based on the headcanon that Harry is actually Snape's son. Rated M for later chapters.
1. Chapter 1

Note: This is my first real fanfic and my first one co-writing with a friend. I hope you like it and please review!

Disclaimer: I do not own any of the characters or places in this story. Everything belongs to J.K. Rowling, but the story, of course, is mine. :)

As they lay in the grass, looking up at the stars, Lily asked Severus what he thought they were made of.

"Mum says they're giant balls of hot gas," young Lily said.

"Don't believe everything those Muggles tell you," Severus sneered. "My best mate at Hogwarts swears they're the Patronuses of all the wizards who've ever lived."

Lily looked puzzled. "You mean all of the wizards who've ever died?"

"Something like that."

"I hope that when we die, ours will be right next to each other."

"That would be nice." Snape blushed a deep scarlet, painfully obvious on his pale complexion, even by moonlight.

"Tell me about the Patronuses again." Lily asked.

"Well, they're a wizard's most powerful protection. They take the form of an animal and they protect you when you cast the Patronus charm. Love is probably the only thing more powerful; at least according to Dumbledore."

Severus slid his hand across the grass to find Lily's but she withdrew it to her fine red hair before he could touch it.

"Lily."

The word sounded so sweet on his lips but there was something wrong.

"Lily."

It wasn't his voice.

"Lily…"

Lily jolted awake with a start. It was James whispering her name.

"It's time to wake up, love. We need to go to that Order meeting today."

"Right," said Lily sitting up. "I almost forgot about that."

Lily gave James and quick peck and quickly jumped out of bed to go take a shower.

She turned on the water and hopped in; the dream weighed heavily on Lily's mind. She hadn't talked to Severus in months; he had stopped making contact with her after she and James had gotten married. Lily had sent a few letters to him but her owl always turned up empty handed.

_Maybe I need to pay him a visit, _thought Lily. _He must miss me as dearly as I miss him. Perhaps there'll be time after the meeting. _

Scrubbing shampoo into her hair, Lily started to formulate her plan for a visit but she needed an excuse to be out of the house; she knew James didn't like Snape or Lily's friendship with him. Suddenly an idea came to her.

"So I'm thinking of visiting Petunia this afternoon," Lily whispered to James during the Order meeting.

"Are you mad?" He whispered back. "The woman hates you and wouldn't even come to our wedding."

"Oh come on," Lily begged. "She's my sister and whether she likes me or not, we're family."

James gave her a hesitant look. McGonagall cleared her throat across the table, silencing the both of them.

"I need to see her." Lily continued on their way home. "Just a short afternoon visit. Tomorrow. You and Sirius could go see a Quidditch match."

"It almost sounds as if you're trying to get rid of me." James took Lily in his arms. "Is there another man I should be worried about?"

"Of course not!" said Lily, pecking him on the cheek. A feeling of guilt rushed through her. She loved James dearly but she also loved her childhood friend.

Lily saw James off in the morning as he and Sirius left to go watch the latest Quidditch match. As soon as she was sure that they were gone she quickly grabbed her jacket and wand and apparated on the spot.

Saying she was going to Petunia's was a perfect lie because Severus really didn't live that far from Petunia herself.

Lily appeared in front of the old playground she and her sister had played on years ago and where she had first met Severus.

"_It's obvious, isn't it?" _

"_What's obvious?" asked Lily. _

"_You're… you're a witch," whispered Snape. _

Lily closed her eyes, fighting back tears. Those reminiscent days had been so wonderful. Why did things have to go the way they did? Why couldn't James have just left Severus alone? Why did Severus have to choose the Death Eaters?

All these thoughts ran through Lily's mind as she walked down the road towards Spinner's End.

She finally reached his house and knocked on the door. A moment passed before she heard movement behind the door and suddenly a tall, lean face appeared before her.

"Sev."


	2. Chapter 2

Here's the next chapter. Sorry it took so long! Please read and review. The next chapter will be well worth the wait. ;)

"L- Lily! What are you doing here?" asked Severus.

"I had to see you," said Lily with a piercing gaze. "You don't answer any of my letters and I- I miss you."

Severus looked bewildered. He hadn't seen the woman he loved in over a year and here she was standing on his doorstep. _Goodness, I must look a fright_, thought Severus. But Lily was paying no mind to his disheveled appearance.

Severus quickly composed himself. "Come in."

Snape's house was as dark and brooding as Lily remembered it as a child. There were books everywhere and things sitting in jars that looked like they belonged in an apothecary instead of a living room. Lily noticed a book lying open on a coffee table and saw that it was an old book of potions.

"I see you're trying to make Wolfsbane," commented Lily, "Any particular reason?"

"Oh," said Severus, slightly embarrassed. "No. I was just practicing for… um… educational purposes."

"Right," said Lily, not believing a word he said. She knew of his involvement with the Death Eaters and had no desire to know what that potion was being used for. Truth be told she missed making potions so regularly at Hogwarts. Ever since they had graduated, Lily had made a few potions here and there to keep her mind off of Order business and sometimes for Order missions themselves, but she missed having a challenge. Nowadays everything they did was dedicated to the Order and trying to stop He-Who-Must-Not-Be-Named. It felt good to be working to fight evil but it could be exhausting.

"Do you miss it?" asked Lily.

"What?" Snape had just put a kettle on for tea and dropped the lid in nervousness.

"Hogwarts," replied Lily. "I miss it terribly. Making potions all the time, the feasts every day in the Great Hall, my friends…" Lily cast a sidelong glance at Severus but he avoided her gaze.

"Um…" started Snape as he quickly boiled the tea with magic, "Yes, I believe I do. But I am glad to be rid of your insufferable husband and his constant torment."

Lily gratefully took a cup of tea but with a feeling of guilt. She knew all too well of the feud between him and James. Her friendship with Severus had never been the same after he had called her a Mudblood. That fateful day had put a strain on their friendship that had never quite recovered and now, here she was, in Sev's sitting room.

"I didn't come here to fight. I came here because I miss you and I want my friend back."

"You could have sent an owl and at least given me a chance to tidy up first."

Lily laughed ironically, "Yes, but you never answer them! This was the only way I could make sure I would see you."

Severus looked down at his cup of tea. He missed Lily too and he longed to tell her all the things he never got to say, but fear kept him at bay.

"What about your husband? Won't he be worried you're here? I'd expect him to be breaking down the door any minute now."

"He doesn't know I'm here."

Snape looked up at her questioningly but her strong gaze told him she was telling the truth.

"I'm sorry," whispered Snape after a moment of quiet. "It was wrong of me not to write back."

Lily and Severus drank their tea in an awkward silence before Lily finally broke it.

"Why didn't you come to my wedding or at least come and visit? You're my oldest friend, Sev, and I wanted you to be there."

Severus just stared at his tea while Lily talked.

"It was really cruel of you to do this to me. I've forgiven you for that incident all those years ago but you can't even write me a little note and tell me you're doing alright? I've been worried sick about you. You know I'm in the Order. I hear things, Sev; bad things. Every time we get a report on more Death Eaters being taken down, I pray it's not you. I couldn't bear it if something happened to you."

"I'm sorry Lily," said Severus, tears silently filling his eyes. "I've missed you more than you can imagine but I was too ashamed to ever write back. I've never been able to forget that fight back at Hogwarts. I'm such a coward. How could you ever forgive me for my mistake if I can't even forgive myself?"

Tears were streaming down his face, but he refused to look up at her.

"Sev," whispered Lily.

"I- I can't bear to have you hate me. If I lose you then I have no one; no one!"

Lily looked at him hard. She got up and walked over to him. She put his tea down on the coffee table, taking his hands and looking straight into his eyes, "Sev, you are my best friend and I don't ever want you to forget it. I love you."

Severus finally found the courage to look up at her. Her beautiful green eyes were filling with tears and he knew she meant every word. How he had longed for the day to hear her say those three words. He had imagined it so many different ways in his dreams, but it didn't matter. After all these years, here she was in front of him and she loved him back.

In a moment of panic, Severus quickly pressed his lips to hers. Lily was taken aback.

"Sev! What the hell do you think you're doing?!"

Severus looked down in embarrassment and guilt. "I'm sorry. I've just missed you so much and there are so many things I wish I could have told you."

"Really?" questioned Lily. "Like what?"

Severus met her questioning gaze, "Like how your eyes sparkle like emeralds when you laugh. And when you laugh it sounds like a bird singing. I've missed that."

Lily blushed slightly and looked away. "Sev…"

"No! It's true!" protested Snape. "And you find the truth in things. You tell everyone how wonderful and different they are without the slightest hint of irony, and the funny thing is, everyone believes you because it's true. You're special, Lily."

Lily timidly looked up at him. "You mean it?"

"With all my heart."

Lily loved James dearly but she also loved Sev, her best friend, the first person to truly understand her, the one that never left her side, even after all this time. Confused, dazed, and on a sudden whim of emotion, Lily closed the gap between them and pressed her lips gingerly against his.

Severus jumped back in surprise and then returned the kiss. This was better than the best dream he had ever imagined. Lily, his Lily, was actually kissing him! Severus pulled away for a moment stare into those beautiful green eyes.

"Oh Lily," said Severus, placing a hand on her cheek.

Lily was at a loss for words. She knew deep down that this was wrong, but she missed her friend terribly and something about this just felt right.

"Shh," she replied. Severus looked down at her full lips and took them with his once more. He wrapped her in his arms and slowly they started making their way into the other room.


End file.
